Even with many advances in its instrumentation and method, X-ray diffraction still requires large protein crystals which are very difficult to get. There are many, many proteins structural projects which are abandoned because the crystals obtained are small. In this project, we ask for funds to buy, off the shelf equipment, in order to set-up a high speed data collection system that can still collect good data from these small crystals in order to solve the structure of these proteins. This system will use a special X-ray generator with the highest brilliance source capable of a 3.5 Kw power at a very small focus (.1 mm x .lmm). For X-ray detection we plan to use the multiwire area detectors available in our laboratory. Once finished, this Mark IV System for small protein cystals will be placed in the Univ. of California, San Diego Resource for Protein Crystallography. Any protein crystallography group can request time to use it. However, we have outlined the research projects of 6 possible research groups. The outlined research projects involve the three-Dimensional structure studies of many interesting enzymes including the enzymes from the A.I.D.S. virus.